After marijuana use became legal, consumption nearly tripled among 18- to 20-year-olds. As awareness of the harm of marijuana grew, the number of cannabis coffeehouses in the Netherlands decreased 36 percent in six years.
Almost all Dutch towns have a cannabis policy, and 73 percent of them have a no-tolerance policy toward the coffeehouses.
In 1987 Swiss officials permitted drug use and sales in a Zurich park, which was soon dubbed Needle Park, and Switzerland became a magnet for drug users the world over. Within five years, the number of regular drug users at the park had reportedly swelled from a few hundred to 20,000.
The area around the park became crime-ridden to the point that the park had to be shut down and the experiment terminated.
Smoking Rates Increased Among Teens
Marijuana use by Canadian teenagers is at a 25-year peak in the wake of an aggressive decriminalization movement. At the very time a decriminalization bill was before the House of Commons, the Canadian government released a report showing that marijuana smoking among teens is "at levels that we haven't seen since the late '70s when rates reached their peak."After a large decline in the 1980s, marijuana use among teens increased during the 1990s, as young people apparently became "confused about the state of federal pot laws."

